Collaboration events such as videoconferences can occur over a data network (such as, for example, the Internet, wide area networks or local area networks). During some such events, multiple users may be sharing video, audio and other data with multiple other users. Videoconferences are typically conducted over a conference server or bridge. All attendees connect to the server, and the server routes audio and video data between the users. Depending on the scale of the event, very large amounts of data may be shared. This can strain network and participant resources. Also, the large number of streams being communicated can complicate the event and make it difficult for users to effectively communicate with one another. These and other problems may be particularly acute when conferences involve users that are locally connected to different conference servers.